Dielectric composition, dielectric element, electronic component, and multilayer electronic component

ABSTRACT

A dielectric composition with high voltage resistance and favorable reliability, and an electronic component using the dielectric composition. The dielectric composition contains, as a main component, a tungsten bronze type composite oxide represented by a chemical formula (Sr 1.00−s−t Ba s Ca t ) 6.00−x R x (Ti 1.00−a Zr a ) x+2.00 (Nb 1.00−b Ta b ) 8.00−x O 30.00  in which the R is at least one element selected from Y, La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu, and s, t, x, a, and b satisfy 0.50≤s≤1.00, 0≤t≤0.50, 0.50≤s+t≤1.00, 0.50&lt;x≤1.50, 0.30≤a≤1.00, and 0≤b≤1.00. At least one or more elements selected from Mn, Mg, Co, V, W, Mo, Si, Li, B, and Al are contained as a sub component in 0.10 mol or more and 20.00 mol or less with respect to 100 mol of the main component.

TECHNICAL FIELD

The present invention relates to a dielectric composition, a dielectric element, an electronic component, and a multilayer electronic component which are suitably used particularly under a high-temperature environment such as in-vehicle use.

BACKGROUND ART

For example, a multilayer ceramic capacitor is used in a variety of electronic equipment because of high reliability and low cost thereof. Specifically, the multilayer ceramic capacitor is used in information terminals, home electronics, and automobile electronic components. In these use applications, particularly, in a multilayer ceramic capacitor for use application of in-vehicle use or the like, as compared to a typical multilayer ceramic capacitor, securement up to a higher-temperature region is required in some cases and higher reliability is necessary. It is necessary that the multilayer ceramic capacitor is not broken against a voltage to be applied, that is, has high voltage resistance. Further, it is also necessary that insulation resistance is less likely to deteriorate even when a voltage is applied for a long time in a high-temperature region, that is, a high-temperature load life is long.

Patent document 1 discloses a dielectric ceramic composition exhibiting a high specific permittivity at room temperature and having high specific resistance even in a high-temperature range of 180° C. Specifically, disclosed is a technology relating to a multilayer ceramic capacitor using a dielectric ceramic composition containing, as a main component, a tungsten bronze type composite oxide represented by a composition formula (K_(1−y)Na_(y))Sr₂Nb₅O₁₅ (provided that, 0≤y<0.2) and containing a first sub component and a second sub component in an amount of 0.1 part by mol or more and 40 parts by mol or less with respect to 100 parts by mol of the main component.

However, as understood from the composition formula, in the patent document 1, potassium (K) and sodium (Na) that are alkali metal elements are contained as constituent elements of the main component. Since the alkali metal has high volatility, there is a problem in that handling at the time of manufacturing is prone to be cumbersome, for example, a process of filling an alkali metal element needs to be introduced in processes.

Further, when the alkali metal with high volatility is contained, there are problems in that a lattice defect caused by the alkali metal easily occurs in the dielectric composition by a binder removal process and a firing process that perform a heat treatment at a high temperature, or a reoxidation process, and high voltage resistance is difficult to obtain. Therefore, in the patent document 1, there is no disclosure of a technology relating to a high specific permittivity and high voltage resistance in the high-temperature region.

Further, patent document 2 discloses a technology relating to a ceramic capacitor which includes a dielectric ceramic layer obtained by adding a plurality of additives to a perovskite type oxide formed by a composition formula (Ca_(1−x)(Ba,Sr)_(x))_(k)(Zr_(1−y)Ti_(y))O₃ having a high quality factor Q at 20° C., a favorable temperature coefficient, and high voltage resistance at 150° C.

In the patent document 2, high voltage resistance is exhibited in a high-temperature range of 150° C., but there are problems in that the specific permittivity at 20° C. is only about 125 at a maximum and a desired capacitance is difficult to obtain in a high-temperature region of 175° C. or higher that is expected to be used hereafter.

Further, non-patent document 1 discloses a technology relating to a tungsten bronze type dielectric Ba₂MTi₂Nb₃O₁₅ (M=Bi³⁺, La³⁺, Nd³⁺, Sm³⁺, Gd³⁺) with a high specific permittivity and a small dielectric loss. The tungsten bronze type dielectric has a high specific permittivity at room temperature of about 100 to 700 and a favorable value of tan δ at room temperature of 5% or less. In addition, non-patent document 2 discloses a technology relating to a tungsten bronze type dielectric Ba₂Sm₂Ti₄Ta₆O₃₀ with a high specific permittivity and a small dielectric loss. The tungsten bronze type dielectric has a high specific permittivity at room temperature of about 120 and a favorable value of tan δ at room temperature of 3% or less. However, the non-patent document 1 does not describe a high-temperature load life.

CITATION LIST Patent Document

-   Patent document 1: WO 2006/114914 A -   Patent document 2: JP 11-224827 A

Non-Patent Document

-   Non-patent document 1: JOURNAL OF APPLIED PHYSICS 101, 104114 (2007)     “Dielectric and structural studies of Ba₂MTi₂Nb₃O₁₅ (BMTNO₁₅,     M=Bi³⁺, La³⁺, Nd³⁺, Sm³⁺, Gd³⁺) tetragonal tungsten     bronze-structured ceramics” -   Non-patent document 2: Journal of the American Ceramic Society,     93[3] 782-786 (2010) “Crystal structure and ferroelectric behaviors     of Ba₅SmTi₃Ta₇O₃₀ and Ba₄Sm₂Ti₄Ta₆O₃₀ tungsten bronze ceramics”

SUMMARY OF THE INVENTION Problem to be Solved by the Invention

The present invention is made in view of the above-described problems, and aims to provide a dielectric composition which is suitably used under a high-temperature environment such as in-vehicle use, and has a long high-temperature load life as well as high DC voltage resistance and high specific resistance even under an use environment of 175° C. or higher, and a dielectric element, an electronic component, and a multilayer electronic component which use the dielectric composition.

Means for Solving Problem

In order to achieve the object, a dielectric composition of the present invention contains, as a main component, a tungsten bronze type composite oxide represented by (Sr_(1.00−s−t)Ba_(s)Ca_(t))_(6.00−x)R_(x)(Ti_(1.00−a)Zr_(a))_(x+2.00)(Nb_(1.00−b)Ta_(b))_(8.00−x)O_(30.00),

in which the R is at least one element selected from Y, La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu, and

s, t, x, a, and b satisfy 0.50≤s≤1.00, 0≤t≤0.50, 0.50≤s+t≤1.00, 0.50≤x≤1.50, 0.30≤a≤1.00, and 0≤b≤1.00.

With the above-described dielectric composition, it is possible to obtain a dielectric composition which is suitably used under a high-temperature environment and has a long high-temperature load life as well as high DC voltage resistance and high specific resistance.

As a desirable embodiment of the present invention, a substitution amount a of Zr contained in the main component is preferably 0.50≤a≤1.00. Accordingly, it is possible to obtain a higher specific permittivity as well as higher DC voltage resistance.

Further, as a desirable embodiment of the present invention, at least one selected from Mn, Mg, Co, V, W, Mo, Si, Li, B, and Al is contained as a sub component in 0.10 mol or more and 20.00 mol or less with respect to 100 mol of the main component. Accordingly, higher specific resistance, higher DC voltage resistance, and a higher specific permittivity are obtained.

A dielectric element according to the present invention preferably includes the above-described dielectric composition.

When the dielectric element according to the present invention includes the above-described dielectric composition, the dielectric element can be used under a high-temperature environment such as in-vehicle use.

An electronic component according to the present invention includes a dielectric layer formed by the above-described dielectric composition.

A multilayer electronic component according to the present invention includes a multilayer portion obtained by alternately stacking a dielectric layer formed by the above-described dielectric composition and an internal electrode layer.

When the electronic component and the multilayer electronic component according to the present invention include a dielectric layer formed by the above-described dielectric composition, the electronic component and the multilayer electronic component can be used under a high-temperature environment such as in-vehicle use.

The use application of the electronic component having a dielectric layer formed by the dielectric composition according to the present invention is not particularly limited, but the electronic component is useful for a multilayer ceramic capacitor, a piezoelectric element, a chip varistor, a chip thermistor, and the like.

Effect of the Invention

The present invention can provide a dielectric composition which is suitably used under a high-temperature environment of 175° C. or higher, such as in-vehicle use, and has high DC voltage resistance, a high specific permittivity, high specific resistance, and a long high-temperature load life, and a dielectric element, an electronic component, and a multilayer electronic component which use the dielectric composition.

BRIEF DESCRIPTION OF DRAWINGS

FIGURE illustrates a cross-sectional view of a multilayer ceramic capacitor according to an embodiment of the present invention.

MODE(S) FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the present invention will be described.

A dielectric composition according to the present embodiment contains, as a main component,

a tungsten bronze type composite oxide represented by a chemical formula (Sr_(1.00−s−t)Ba_(s)Ca_(t))_(6.00−x)R_(x)(Ti_(1.00−a)Zr_(a))_(x+2.00)(Nb_(1.00−b)Ta_(b))_(8.00−x)O_(30.00),

in which the R is at least one element selected from Y, La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu, and

s, t, x, a, and b satisfy 0.50≤s≤1.00, 0≤t≤0.50, 0.50≤s+t≤1.00, 0.50≤x≤1.50, 0.30≤a≤1.00, and 0≤b≤1.00.

When the dielectric composition according to the present embodiment contains, as a main component, a tungsten bronze type composite oxide represented by the chemical formula, high voltage resistance is easily obtained. Regarding the reason for this, the present inventors consider as follows. Since the tungsten bronze type composite oxide as the main component of the present embodiment has a characteristic that the bandgap is wide, electrons in the valence band are difficult to excite to the conduction band so that a carrier concentration of electrons that are a majority carrier involved in conduction can be suppressed. In addition, it is considered that the carrier concentration of conduction electrons that are a majority carrier affects electron avalanche that is a typical breakdown mode of the voltage resistance. In the dielectric composition of the present invention, since the carrier concentration of electrons that are a majority carrier can be suppressed to be low, it is considered that breakdown caused by electron avalanche is difficult to occur.

Further, since the bandgap is wide, a certain degree of width of the bandgap can be maintained even when high field strength is applied, and thus it is considered that high voltage resistance is easily obtained even in a high electric field. In addition, since an alkali metal is not contained, a lattice defect is difficult to occur and conduction electrons are difficult to generate so that the dielectric composition of the present invention has a characteristic that the specific resistance and the voltage resistance are high. Further, it is considered that electrolysis reduction reaction is difficult to occur at a high temperature and under a high electric field. For this reason, it is considered that a long high-temperature load life is exhibited since an increase in conduction electron caused by reduction reaction can be suppressed.

When s and tin the chemical formula are 0.50≤s≤1.00, 0≤t≤0.50, and 0.50≤s+t≤1.00, high voltage resistance is easily obtained. Preferably, when s and tin the chemical formula are 0.60≤s≤1.00, 0.20≤t≤0.50, and 0.80≤s+t≤1.00, higher voltage resistance is easily obtained. On the other hand, in a case where K or Na that is an alkali metal element is contained in addition to Sr, Ba, and Ca, since volatility of these elements is high, a lattice defect occurs, and as a result, there is a tendency that high voltage resistance is difficult to obtain. In addition, t represents a substitution amount of Ca. Ca is an arbitrary component and an upper limit of the substitution amount thereof is 0.50. When x in the chemical formula is 0.50<x≤1.50, a long high-temperature load life can be obtained.

When R in the chemical formula is at least one element selected from Y, La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu, high voltage resistance is easily obtained.

When a tungsten bronze type composite oxide in which x in the chemical formula is 0.50<x≤1.50, for example, which is represented by (Sr_(1.00−s−t)Ba_(s)Ca_(t))_(5.00)R_(1.00)(Ti_(1.00−a)Zr_(a))_(3.00)(Nb_(1.00−b)Ta_(b))_(7.00)O_(30.00) in the case of x=1.00 is used as the main component, a long high-temperature load life is easily obtained.

On the other hand, in a case where x is 0.50 or less or x is more than 1.50, for example, in a composite oxide of a chemical formula Ba₆Ti₂Nb₈O₃₀, a chemical formula Ba₄La₂Ti₄Nb₆O₃₀, or the like, the high-temperature load life is shortened.

When a substitution amount a of Zr in the chemical formula is 0.30≤a≤1.00, the bandgap is widened, and thus high voltage resistance is easily obtained. On the other hand, in a case where the substitution amount a is less than 0.30, the bandgap is difficult to widen, and as a result, high voltage resistance is difficult to obtain.

Further, when the substitution amount a of Zr in the chemical formula is 0.50≤a≤1.00, the bandgap is further widened, and thus high voltage resistance is easily obtained.

Also in a composite oxide in which Nb in the chemical formula is substituted with Ta, a tungsten bronze type crystal structure can be maintained, and when a substitution amount b of Ta is set to 0.10≤b≤1.00, higher voltage resistance is easily obtained.

As the sub component, it is preferable that at least one or more elements selected from Mn, Mg, Co, V, W, Mo, Si, Li, B, and Al are contained. Owing to an interaction between Zr contained in the main component and there elements, high voltage resistance and high specific resistance are easily obtained. Preferably, when the substitution amount a of Zr is set to 0.80≤a≤1.00, the interaction is enhanced so that higher voltage resistance is easily obtained.

Further, when the amount of the sub component is set to 0.10 mol or more and 20.00 mol or less with respect to 100 mol of the main component, high specific resistance of 9.00×10¹² Ωcm or more can be obtained at 200° C. Moreover, higher voltage resistance can be obtained even at a high temperature of 175° C. or higher.

Further, other than R contained in the main component, at least one element selected from Y, La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu may be contained as a second sub component. The second sub component is an arbitrary component and an upper limit of the amount thereof is determined in a range within which the object of the invention can be achieved.

Incidentally, the dielectric composition may further contain fine impurities or other sub components as long as they do not deteriorate dielectric properties that are the effects of the present invention, that is, the specific permittivity, the specific resistance, and the voltage resistance. Therefore, the amount of the main component is not particularly limited, and for example, is 50 mol % or more and 100 mol % or less with respect to the whole dielectric composition containing the main component.

Next, description will be given using a multilayer ceramic capacitor as an example. FIGURE illustrates a multilayer ceramic capacitor according to an embodiment of the present invention. A multilayer ceramic capacitor 1 has a capacitor element main body 10 having a configuration in which a dielectric layer 2 and an internal electrode layer 3 are alternately stacked. A pair of external electrodes 4, which is conductive with each of the internal electrode layers 3 alternately disposed inside the element main body 10, is formed at both ends of the capacitor element main body 10. The shape of the capacitor element main body 10 is not particularly limited, and is typically a rectangular parallelepiped shape. In addition, the dimension thereof is also not particularly limited, and the dimension may be appropriately determined depending on the use application.

The thickness of the dielectric layer 2 is not particularly limited, and may be appropriately determined depending on the use application of the multilayer ceramic capacitor 1.

The conductive material contained in the internal electrode layer 3 is not particularly limited, and is preferably Ni, Pd, Ag, a Pd—Ag alloy, Cu, or a Cu-based alloy. Incidentally, a trace amount of various components such as P may be contained in about 0.1% by weight or less in Ni, Pd, Ag, a Pd—Ag alloy, Cu, or a Cu-based alloy. In addition, the internal electrode layer 3 may be formed using a commercially available paste for an electrode. The thickness of the internal electrode layer 3 may be appropriately determined depending on the use application or the like.

Next, an example of a method for manufacturing the multilayer ceramic capacitor illustrated in FIGURE will be described.

The multilayer ceramic capacitor 1 of the present embodiment is manufactured by producing a green chip by a typical printing method or sheet method using a paste, firing the green chip, then applying an external electrode to the green chip, and firing the obtained product, similarly to a multilayer ceramic capacitor of the related art. Hereinafter, the manufacturing method will be described in detail.

An example of the method for manufacturing the multilayer ceramic capacitor according to the present embodiment will be described.

First, raw materials are prepared such that the main component has a desired proportion, and are mixed and heat-treated (calcined) at 800° C. or higher. Thus, calcined powder can be obtained. Preferably, a heat treatment is performed at 800° C. to 1000° C. such that the particle size of the calcined powder is 0.1 μm or more and 5.0 μm or less. It is preferable that a different phase such as Ba₅Nb₄O₁₅ having an anisotropic shape is not contained in the calcined powder.

Regarding the raw materials, an oxide mainly configured by Sr, Ba, Ca, Ti, Zr, Nb, or Ta, or a mixture thereof can be used as raw material powder. Moreover, the raw materials can be appropriately selected from various compounds that become the aforementioned oxide or composite oxide by firing, for example, carbonate, oxalate, nitrate, hydroxide, an organometallic compound, and the like and can be mixed for use. Specifically, SrO or SrCO₃ may be used as a raw material of Sr.

Further, in a case where the dielectric composition according to the present embodiment contains the above-described sub component, a raw material of the sub component is also prepared. The raw material of the sub component is not particularly limited, and oxides of respective components or mixtures thereof can be used as raw material powder. Moreover, the raw materials can be appropriately selected from various compounds that become the aforementioned oxide or composite oxide by firing, for example, carbonate, oxalate, nitrate, hydroxide, an organometallic compound, and the like and can be mixed for use. Specifically, MgO or MgCO₃ may be used as a raw material of Mg.

The prepared calcined powder of the main components and the raw material of the sub component are weighed to have a predetermined compositional ratio and mixed, thereby obtaining a dielectric composition raw material. Examples of a mixing method include wet mixing performed using a ball mill and dry mixing performed using a dry mixer.

This dielectric composition raw material is prepared in the form of a coating material to prepare a paste for a dielectric layer. The paste for a dielectric layer may be an organic coating material obtained by kneading a dielectric raw material and an organic vehicle or may be an aqueous coating material.

The organic vehicle is obtained by dissolving a binder in an organic solvent. The binder used in the organic vehicle is not particularly limited, and may be appropriately selected from typical various binders such as ethylcellulose and polyvinyl butyral. The organic solvent to be used is also not particularly limited, and may be appropriately selected from various organic solvents such as terpineol, butyl carbitol, and acetone depending on a method to be used such as a printing method or a sheet method.

Further, in a case where the paste for a dielectric layer is produced in the form of an aqueous coating material, an aqueous vehicle obtained by dissolving a water-soluble binder, a dispersant, or the like in water and a dielectric raw material may be kneaded. The water-soluble binder used in the aqueous vehicle is not particularly limited, and for example, polyvinyl alcohol, cellulose, a water-soluble acrylic resin, and the like may be used.

A paste for an internal electrode layer is prepared by kneading the above-described organic vehicle with conductive materials formed from various conductive metals or alloys described above, various oxides, which become the above-described conductive material after firing, an organometallic compound, resinate, or the like.

A paste for an external electrode may be prepared in the similar manner to the paste for an internal electrode layer described above.

The amount of the organic vehicle in each paste described above is not particularly limited, and may be a typical amount, for example, the amount of the binder may be about 1% by weight to 5% by weight and the amount of the solvent may be about 10% by weight to 50% by weight. In addition, additives selected from various dispersants, plasticizers, dielectric materials, insulator materials, and the like may be contained in each paste as necessary. The total amount of these additives is set to preferably 10% by weight or less.

In the case of using a printing method, the paste for a dielectric layer and the paste for an internal electrode layer are printed on a substrate such as PET, stacked, cut in a predetermined shape, and then peeled off from the substrate to obtain a green chip.

Further, in the case of using a sheet method, a green sheet is formed using the paste for a dielectric layer, the paste for an internal electrode layer is printed on the green sheet, and then these are stacked to obtain a green chip.

The green chip is subjected to a binder removal treatment before firing described later. As binder removal conditions, a temperature increase rate is set to preferably 5° C./hr to 300° C./hr, a retention temperature is set to preferably 180° C. to 500° C., and a temperature retention time is set to preferably 0.5 hours to 24 hours. In addition, the atmosphere of the binder removal treatment is set to air or reductive atmosphere.

Further, the retention temperature at the time of firing is preferably 1000° C. to 1400° C. and more preferably 1100° C. to 1360° C. When the retention temperature is less than the above ranges, densification is not sufficient. When the retention temperature exceeds the above ranges, disconnection of the electrode by abnormal sintering of the internal electrode layer and deterioration in capacity change ratio by diffusion of an internal electrode layer constituent material easily occur. In addition, when the retention temperature exceeds the above ranges, there is a concern that dielectric particles coarsen to decrease voltage resistance.

As firing conditions other than the above firing conditions, in order to achieve uniform firing of a chip, the temperature increase rate is set to preferably 50° C./hr to 500° C./hr and more preferably 200° C./hr to 300° C./hr, and in order to control the particle diameter distribution after sintering within a range of 0.1 μm to 10.0 μm, the temperature retention time is set to preferably 0.5 hours to 24 hours and more preferably 1 hour to 3 hours, and the cooling rate is set to preferably 50° C./hr to 500° C./hr and more preferably 200° C./hr to 300° C./hr.

In the above-described binder removal treatment, for example, a wetter or the like may be used in wetting of N₂ gas, mixed gas, or the like. In this case, the water temperature is preferably about 5° C. to 75° C. In addition, the binder removal treatment, firing, and annealing may be performed consecutively or independently.

The capacitor element main body obtained as described above is polished at the end faces thereof, for example, by barrel polishing, sandblasting, or the like and the paste for an external electrode is applied and fired, thereby forming the external electrode 4. Then, as necessary, a coating layer is formed on the surface of the external electrode 4 by plating or the like.

Hereinbefore, the embodiments of the present invention have been described. The present invention is not limited to the aforementioned embodiments, and can be variously modified in a range not departing from the gist of the present invention.

EXAMPLES

Hereinafter, the present invention will be described in more detail by means of specific examples of the present invention. The present invention is not limited to these examples. Incidentally, specimens marked with ※ in Table 2 are outside the range of the present invention.

As a raw material of the main component, each powder of SrCO₃, BaCO₃, CaCO₃, TiO₂, ZrO₂, Nb₂O₅, Ta₂O₅, Y₂O₃, La₂O₃, Pr₂O₃, Nd₂O₃, Sm₂O₃, Eu₂O₃, Gd₂O₃, Tb₂O₃, Dy₂O₃, Ho₂O₃, Er₂O₃, Tm₂O₃, Yb₂O₃, and Lu₂O₃ was prepared.

These materials were weighed to have the main component composition in Table 1, then wet-mixed with a ball mill, dried, and calcined at 800° C. to obtain calcined powder of the main component. A dielectric composition raw material was prepared. As a raw material of the sub component, each powder of SiO₂, MgO, Co₂O₃, V₂O₅, WO₃, MoO₃, MnO, Li₂CO₃, B₂O₃, Al₂O₃, and Fe₃O₄ was prepared and the main components and the sub components were mixed to respectively have a proportion in Table 1 to obtain dielectric composition raw materials of Specimen No. 1 to Specimen No. 65.

TABLE 1 Accessory component [mol %] (with respect to 100 mol of main component) 1-s-t s t Re x a b Si Specimen No. 1 0.40 0.60 0.00 La 1.00 0.30 0.00 — Specimen No. 2 0.50 0.50 0.00 La 1.00 0.30 0.00 — ^(※)Specimen No. 3 0.60 0.40 0.00 La 1.00 0.30 0.00 — ^(※)Specimen No. 4 1.00 0.00 0.00 La 1.00 0.30 0.00 — Specimen No. 5 0.40 0.50 0.10 La 1.00 0.30 0.00 — Specimen No. 6 0.30 0.50 0.20 La 1.00 0.30 0.00 — Specimen No. 7 0.00 0.50 0.50 La 1.00 0.30 0.00 — ^(※)Specimen No. 8 0.00 0.40 0.60 La 1.00 0.30 0.00 — Specimen No. 9 0.00 0.60 0.40 La 1.00 0.30 0.00 — Specimen No. 10 0.20 0.60 0.20 La 1.00 0.30 0.00 — ^(※)Specimen No. 11 0.10 0.80 0.10 La 0.50 0.30 0.00 — Specimen No. 12 0.10 0.80 0.10 La 0.51 0.30 0.00 — Specimen No. 13 0.10 0.80 0.10 La 1.00 0.30 0.00 — Specimen No. 14 0.10 0.80 0.10 La 1.50 0.30 0.00 — ^(※)Specimen No. 15 0.10 0.80 0.10 La 1.75 0.30 0.00 — Specimen No. 16 0.10 0.80 0.10 Y 1.00 0.30 0.00 — Specimen No. 17 0.10 0.80 0.10 Pr 1.00 0.30 0.00 — Specimen No. 18 0.10 0.80 0.10 Nd 1.00 0.30 0.00 — Specimen No. 19 0.10 0.80 0.10 Sm 1.00 0.30 0.00 — Specimen No. 20 0.10 0.80 0.10 Eu 1.00 0.30 0.00 — Specimen No. 21 0.10 0.80 0.10 Gd 1.00 0.30 0.00 — Specimen No. 22 0.10 0.80 0.10 Tb 1.00 0.30 0.00 — Specimen No. 23 0.10 0.80 0.10 Dy 1.00 0.30 0.00 — Specimen No. 24 0.10 0.80 0.10 Ho 1.00 0.30 0.00 — Specimen No. 25 0.10 0.80 0.10 Er 1.00 0.30 0.00 — Specimen No. 26 0.10 0.80 0.10 Tm 1.00 0.30 0.00 — Specimen No. 27 0.10 0.80 0.10 Yb 1.00 0.30 0.00 — Specimen No. 28 0.10 0.80 0.10 Lu 1.00 0.30 0.00 — Specimen No. 29 0.10 0.80 0.10 La, Sm 1.00 0.30 0.00 — ^(※)Specimen No. 30 0.10 0.80 0.10 Bi 1.00 0.30 0.00 — ^(※)Specimen No. 31 0.10 0.80 0.10 La 1.00 0.00 0.00 — ^(※)Specimen No. 32 0.10 0.80 0.10 La 1.00 0.10 0.00 — ^(※)Specimen No. 33 0.10 0.80 0.10 La 1.00 0.20 0.00 — Specimen No. 34 0.10 0.80 0.10 La 1.00 0.35 0.00 — Specimen No. 35 0.10 0.80 0.10 La 1.00 0.50 0.00 — Specimen No. 36 0.10 0.80 0.10 La 1.00 0.80 0.00 — Specimen No. 37 0.10 0.80 0.10 La 1.00 1.00 0.00 — Specimen No. 38 0.10 0.80 0.10 La 1.00 0.30 0.05 — Specimen No. 39 0.10 0.80 0.10 La 1.00 0.30 0.10 — Specimen No. 40 0.10 0.80 0.10 La 1.00 0.30 0.50 — Specimen No. 41 0.10 0.80 0.10 La 1.00 0.30 1.00 — Specimen No. 42 0.10 0.80 0.10 La 1.00 0.30 0.00 0.05 Specimen No. 43 0.10 0.80 0.10 La 1.00 0.30 0.00 0.10 Specimen No. 44 0.10 0.80 0.10 La 1.00 0.30 0.00 1.00 Specimen No. 45 0.10 0.80 0.10 La 1.00 0.30 0.00 10.00  Specimen No. 46 0.10 0.80 0.10 La 1.00 0.30 0.00 20.00  Specimen No. 47 0.10 0.80 0.10 La 1.00 0.30 0.00 30.00  Specimen No. 48 0.10 0.80 0.10 La 1.00 0.30 0.00 — Specimen No. 49 0.10 0.80 0.10 La 1.00 0.30 0.00 — Specimen No. 50 0.10 0.80 0.10 La 1.00 0.30 0.00 — Specimen No. 51 0.10 0.80 0.10 La 1.00 0.30 0.00 — Specimen No. 52 0.10 0.80 0.10 La 1.00 0.30 0.00 — Specimen No. 53 0.10 0.80 0.10 La 1.00 0.30 0.00 — Specimen No. 54 0.10 0.80 0.10 La 1.00 0.30 0.00 — Specimen No. 55 0.10 0.80 0.10 La 1.00 0.30 0.00 — Specimen No. 56 0.10 0.80 0.10 La 1.00 0.30 0.00 — Specimen No. 57 0.10 0.80 0.10 La 1.00 0.30 0.00 — Specimen No. 58 0.10 0.80 0.10 La 1.00 0.30 0.00 5.00 Specimen No. 59 0.10 0.80 0.10 La 1.00 0.30 0.00 — ^(※)Specimen No. 60 0.10 0.80 0.10 La 1.00 0.00 1.00 10.00  Specimen No. 61 0.10 0.80 0.10 Pr 1.00 0.80 0.00 5.00 Specimen No. 62 0.10 0.80 0.10 Nd 1.00 1.00 1.00 — Specimen No. 63 0.00 0.50 0.50 Y 1.00 0.30 0.00 — Specimen No. 64 0.00 0.50 0.50 Y 1.00 0.30 0.10 — Specimen No. 65 0.00 0.50 0.50 Y 1.00 0.30 0.00 — Accessory component [mol %] (with respect to 100 mol of main component) Mg Co V W Mo Mn Li B Al Fe Specimen No. 1 — — — — — — — — — — Specimen No. 2 — — — — — — — — — — ^(※)Specimen No. 3 — — — — — — — — — — ^(※)Specimen No. 4 — — — — — — — — — — Specimen No. 5 — — — — — — — — — — Specimen No. 6 — — — — — — — — — — Specimen No. 7 — — — — — — — — — — ^(※)Specimen No. 8 — — — — — — — — — — Specimen No. 9 — — — — — — — — — — Specimen No. 10 — — — — — — — — — — ^(※)Specimen No. 11 — — — — — — — — — — Specimen No. 12 — — — — — — — — — — Specimen No. 13 — — — — — — — — — — Specimen No. 14 — — — — — — — — — — ^(※)Specimen No. 15 — — — — — — — — — — Specimen No. 16 — — — — — — — — — — Specimen No. 17 — — — — — — — — — — Specimen No. 18 — — — — — — — — — — Specimen No. 19 — — — — — — — — — — Specimen No. 20 — — — — — — — — — — Specimen No. 21 — — — — — — — — — — Specimen No. 22 — — — — — — — — — — Specimen No. 23 — — — — — — — — — — Specimen No. 24 — — — — — — — — — — Specimen No. 25 — — — — — — — — — — Specimen No. 26 — — — — — — — — — — Specimen No. 27 — — — — — — — — — — Specimen No. 28 — — — — — — — — — — Specimen No. 29 — — — — — — — — — — ^(※)Specimen No. 30 — — — — — — — — — — ^(※)Specimen No. 31 — — — — — — — — — — ^(※)Specimen No. 32 — — — — — — — — — — ^(※)Specimen No. 33 — — — — — — — — — — Specimen No. 34 — — — — — — — — — — Specimen No. 35 — — — — — — — — — — Specimen No. 36 — — — — — — — — — — Specimen No. 37 — — — — — — — — — — Specimen No. 38 — — — — — — — — — — Specimen No. 39 — — — — — — — — — — Specimen No. 40 — — — — — — — — — — Specimen No. 41 — — — — — — — — — — Specimen No. 42 — — — — — — — — — — Specimen No. 43 — — — — — — — — — — Specimen No. 44 — — — — — — — — — — Specimen No. 45 — — — — — — — — — — Specimen No. 46 — — — — — — — — — — Specimen No. 47 — — — — — — — — — — Specimen No. 48 1.00 — — — — — — — — — Specimen No. 49 — 1.00 — — — — — — — — Specimen No. 50 — — 1.00 — — — — — — — Specimen No. 51 — — — 1.00 — — — — — — Specimen No. 52 — — — — 1.00 — — — — — Specimen No. 53 — — — — — 1.00 — — — — Specimen No. 54 — — — — — — 1.00 — — — Specimen No. 55 — — — — — — — 1.00 — — Specimen No. 56 — — — — — — — — 1.00 — Specimen No. 57 — — — — — — — — — 1.00 Specimen No. 58 — — 3.00 — — 3.00 — — — — Specimen No. 59 5.00 1.00 1.00 — 0.05 — — 10.00  — — ^(※)Specimen No. 60 — — — — — — — — — — Specimen No. 61 — — — — — — — — — — Specimen No. 62 — — — — — — — 5.00 — — Specimen No. 63 — — — — — — — — — — Specimen No. 64 — — — — — — — — — — Specimen No. 65 — — — 1.00 — — — — — — “—” described in Table 1 indicates that the corresponding component is not contained.

The dielectric composition raw material thus obtained (100 parts by weight), a polyvinyl butyral resin (10 parts by weight), dibutyl phthalate (DOP) (5 parts by weight) as a plasticizer, and alcohol (100 parts by weight) as a solvent were mixed with a ball mill to obtain a paste, thereby producing a paste for a dielectric layer.

Further, apart from the above, Pd particles (44.6 parts by weight), terpineol (52 parts by weight), ethylcellulose (3 parts by weight), and benzotriazole (0.4 part by weight) were kneaded with a three-roll mill to obtain a slurry, thereby producing a paste for a Pd internal electrode layer. In addition, similarly to the paste for a Pd internal electrode layer, a paste for a Ni internal electrode layer was produced using Ni particles.

Then, a green sheet was formed using the produced paste for a dielectric layer on a PET film to have a thickness after drying of 7 μm. Subsequently, an internal electrode layer was printed with a predetermined pattern using the paste for an internal electrode layer on the green sheet, and then the sheet was peeled off from the PET film to produce a green sheet having an internal electrode layer. Incidentally, the green sheets each having an internal electrode layer were produced while the paste for a Pd internal electrode layer was used in the green sheets using Specimen No. 1 to Specimen No. 62 and the paste for a Ni internal electrode layer was used in the green sheets using Specimen No. 63 to Specimen No. 65. Subsequently, a plurality of green sheets having an internal electrode layer were stacked and adhered by pressure to obtain a green multilayer body. This green multilayer body was cut in a predetermined size to obtain a green chip.

Then, the obtained green chip was subjected to a binder removal treatment (temperature increase rate: 10° C./hr, retention temperature: 400° C., temperature retention time: 8 hours, atmosphere: in air) and then subjected to firing (temperature increase rate: 200° C./hr, retention temperature: 1000 to 1400° C., temperature retention time: 2 hours, cooling rate: 200° C./hr, atmosphere: in air) to obtain a multilayer ceramic fired body.

The crystal structure of the dielectric layer of the obtained multilayer ceramic sintered body was subjected to X-ray diffraction (XRD) measurement, and as a result, it was confirmed that the tungsten bronze type composite oxide was obtained. In addition, the composition of the dielectric composition in the dielectric layer of the obtained capacitor element main body was measured by inductively coupled plasma source mass spectrometry (ICP-MS), and as a result, it was confirmed that the composition in Table 1 was obtained.

The end faces of the obtained multilayer ceramic fired body were polished by sandblasting, and then an In—Ga eutectic alloy was applied as an external electrode to obtain multilayer ceramic capacitors of Specimen No. 1 to Specimen No. 65 having the same shape as the multilayer ceramic capacitor illustrated in FIGURE. The sizes of the obtained multilayer ceramic capacitors were all 3.2 mm×1.6 mm×1.2 mm, the thickness of the dielectric layer was set to 5.0 μm, the thickness of the internal electrode layer was set to 1.5 μm, and the number of the dielectric layers interposed between the internal electrode layers was set to 10.

The voltage resistance, the specific permittivity (εs), the specific resistance, and the high-temperature load life of the obtained multilayer ceramic capacitors of Specimen No. 1 to Specimen No. 65 were measured by the following methods and presented in Table 2.

[Specific Permittivity (εs)]

The capacitance C was measured for the multilayer ceramic capacitor at 25° C. and 200° C. by a digital LCR meter (4284A manufactured by YHP) at a frequency of 1 kHz with a signal, which has an input signal level (measurement voltage) of 1 Vrms, being input. Then, the specific permittivity εS (no unit of quantity required) was calculated on the basis of the thickness of the dielectric layer, the effective electrode area, and the capacitance C obtained as a result of the measurement. A higher specific permittivity was preferable and the specific permittivity of 500 or more was determined to be favorable.

[Specific Resistance]

Insulation resistance was measured for the multilayer ceramic capacitor specimen at 180° C. and 200° C. by a digital resistance meter (R8340 manufactured by ADVANTEST CORPORATION) under conditions of a measurement voltage of 30 V and a measurement time of 60 seconds. A value of specific resistance was calculated from the electrode area of the capacitor specimen and the thickness of the dielectric layer. Higher specific resistance was preferable, and the specific resistance was determined to be favorable when the specific resistance was 1.00×10¹² Ωcm or more and more preferably 9.00×10¹² Ωcm or more. When the specific resistance is low, leak current increases in the capacitor and malfunction occurs in an electric circuit.

[Voltage Resistance]

A DC voltage was applied to the multilayer ceramic capacitor specimen at 180° C. and 200° C. at a pressure increase rate of 100 V/sec, and a case where leak current exceeds 10 mA was regarded as DC voltage resistance. Higher DC voltage resistance was preferable, and the DC voltage resistance was determined to be favorable when the DC voltage resistance was 150 V/μm or more, more preferably 160 V/μm or more, and further preferably 175 V/μm or more.

[High-Temperature Load Life]

A DC voltage of 40 V/μm was applied to the multilayer ceramic capacitor specimen at 250° C., and a time until the insulation resistance deteriorates by one-digit was regarded as high-temperature load life. A longer high-temperature load life was preferable, and the high-temperature load life was determined to be favorable when the high-temperature load life was 30 hours or longer and more preferably 40 hours or longer.

TABLE 2 250° C. 25° C. High- 180° C. 200° C. 180° C. 200° C. Specific temperature Specific Specific Voltage Voltage permittivity load life resistance resistance resistance resistance [—] [h] {Ωcm] {Ωcm] [V/μm] [V/μm] Specimen No. 1 611 31 3.26E+13 7.34E+12 160 158 Specimen No. 2 642 36 3.43E+13 7.27E+12 157 152 ^(※)Specimen No. 3 641 36 3.53E+13 7.50E+12 147 141 ^(※)Specimen No. 4 653 35 3.22E+13 7.35E+12 141 137 Specimen No. 5 614 38 3.38E+13 7.40E+12 160 154 Specimen No. 6 618 36 3.18E+13 7.36E+12 154 152 Specimen No. 7 649 34 3.38E+13 7.34E+12 156 152 ^(※)Specimen No. 8 675 37 3.27E+13 7.41E+12 149 143 Specimen No. 9 614 37 3.26E+13 7.36E+12 164 160 Specimen No. 10 621 30 3.19E+13 7.49E+12 163 161 ^(※)Specimen No. 11 622 25 3.27E+13 7.38E+12 159 153 Specimen No. 12 687 35 3.30E+13 7.35E+12 164 158 Specimen No. 13 630 37 3.14E+13 7.41E+12 158 151 Specimen No. 14 641 31 3.28E+13 7.29E+12 162 164 ^(※)Specimen No. 15 608 21 3.17E+13 7.32E+12 163 162 Specimen No. 16 622 32 3.22E+13 7.44E+12 158 154 Specimen No. 17 629 34 3.33E+13 7.38E+12 169 151 Specimen No. 18 636 31 3.41E+13 7.36E+12 159 150 Specimen No. 19 628 33 3.28E+13 7.31E+12 158 151 Specimen No. 20 630 36 3.46E+13 7.29E+12 159 153 Specimen No. 21 610 31 3.17E+13 7.31E+12 157 152 Specimen No. 22 618 30 3.19E+13 7.35E+12 156 154 Specimen No. 23 638 35 3.35E+13 7.27E+12 157 153 Specimen No. 24 618 31 3.19E+13 7.21E+12 158 151 Specimen No. 25 623 33 2.27E+13 7.43E+12 159 150 Specimen No. 26 618 34 3.40E+13 7.41E+12 157 150 Specimen No. 27 627 31 3.31E+13 7.46E+12 156 152 Specimen No. 28 626 34 3.22E+13 7.33E+12 157 151 Specimen No. 29 615 35 3.26E+13 7.42E+12 158 154 ^(※)Specimen No. 30 622 34 3.27E+13 7.30E+12 147 133 ^(※)Specimen No. 31 637 6 2.67E+12 5.31E+11 136 134 ^(※)Specimen No. 32 618 5 3.19E+13 7.36E+12 138 142 ^(※)Specimen No. 33 629 7 3.28E+13 8.41E+12 140 145 Specimen No. 34 635 38 5.81E+13 9.56E+12 160 155 Specimen No. 35 639 38 5.91E+13 9.62E+12 180 175 Specimen No. 36 647 35 6.04E+13 9.73E+12 181 177 Specimen No. 37 647 38 6.21E+13 9.89E+12 182 180 Specimen No. 38 633 35 5.45E+13 9.67E+12 158 155 Specimen No. 39 611 31 5.36E+13 9.64E+12 167 164 Specimen No. 40 620 32 5.46E+13 9.78E+12 168 166 Specimen No. 41 630 30 5.33E+13 9.63E+12 170 170 Specimen No. 42 614 33 5.44E+13 9.33E+12 161 155 Specimen No. 43 638 34 5.26E+13 9.36E+12 173 171 Specimen No. 44 641 32 5.48E+13 9.35E+12 174 172 Specimen No. 45 642 37 5.45E+13 9.51E+12 179 178 Specimen No. 46 633 39 5.37E+13 9.38E+12 176 176 Specimen No. 47 615 36 5.01E+13 9.02E+12 163 158 Specimen No. 48 625 40 5.36E+13 9.36E+12 174 171 Specimen No. 49 619 42 5.51E+13 9.49E+12 174 170 Specimen No. 50 628 43 5.60E+13 9.37E+12 175 168 Specimen No. 51 626 40 5.75E+13 9.51E+12 173 171 Specimen No. 52 628 41 5.63E+13 9.48E+12 171 170 Specimen No. 53 618 44 5.59E+13 9.38E+12 172 171 Specimen No. 54 628 43 5.48E+13 9.48E+12 174 173 Specimen No. 55 629 45 5.38E+13 9.38E+12 171 170 Specimen No. 56 614 41 5.37E+13 9.29E+12 173 172 Specimen No. 57 618 44 5.48E+13 9.51E+12 146 141 Specimen No. 58 617 44 5.47E+13 9.42E+12 179 175 Specimen No. 59 626 43 5.38E+13 9.48E+12 178 176 ^(※)Specimen No. 60 610 38 2.55E+12 5.65E+11 135 136 Specimen No. 61 642 42 3.36E+13 7.37E+12 179 178 Specimen No. 62 641 44 3.14E+13 7.27E+12 178 177 Specimen No. 63 615 31 3.27E+13 7.24E+12 165 167 Specimen No. 64 616 34 3.37E+13 7.27E+12 162 165 Specimen No. 65 611 33 3.31E+13 7.29E+12 165 163

As presented in Table 2, Specimen No. 1, Specimen No. 2, Specimen No. 5 to Specimen No. 7, and Specimen No. 9 to Specimen No. 10 in which the amounts s and t, and 1.00−(s+t) of Ba, Ca, and Sr as the main components are respectively 0.50≤s≤1.00, 0≤t≤0.50, and 0.50≤s+t≤1.00 have a high specific permittivity at 25° C., high specific resistance at 200° C., and high voltage resistance at 200° C. Specimen No. 3 and Specimen No. 4 in which s is less than 0.5 and Specimen No. 8 in which t exceeds 0.5 have low voltage resistance at 200° C.

As presented in Table 2, Specimen No. 12 to Specimen No. 14 in which the substitution amount x of R as the main component is 0.50<x≤1.50 have a long high-temperature load life at 250° C. Specimen No. 11 in which x is 0.50 or less and Specimen No. 15 in which x exceeds 1.50 have a short high-temperature load life.

As presented in Table 2, Specimen No. 13 and Specimen No. 16 to Specimen No. 29 in which R as the main component is at least one element selected from Y, La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu have high voltage resistance at 200° C.

As presented in Table 2, Specimen No. 13 and Specimen No. 34 to Specimen No. 37 in which the substitution amount a of Zr as the main component is 0.30≤a≤1.00 have high voltage resistance at 200° C. Specimen No. 31 to Specimen No. 33 in which a is less than 0.3 have low voltage resistance at 200° C.

As presented in Table 2, it is found that since Specimen No. 38 to Specimen No. 41 in which Nb as the main component is substituted with Ta maintain a tungsten bronze structure, the specific permittivity, the high-temperature load life, and the specific resistance are maintained. In addition, in the case of 0.1≤b≤1.00, it is found that the voltage resistance at 200° C. is high.

As presented in Table 2, Specimen No. 43 to Specimen No. 46 in which the molar quantity of the sub component with respect to 100 mol of the main component is 0.10 mol the sub component 20.00 mol have higher voltage resistance at 200° C.

As presented in Table 2, Specimen No. 44, Specimen No. 48 to Specimen No. 56, Specimen No. 58, and Specimen No. 59 in which at least one selected from Mn, Mg, Co, V, W, Mo, Si, Li, B, and Al is contained as a sub component have higher specific resistance at 200° C. In addition, Specimen No. 43 in which at least one selected from Mn, Mg, Co, V, W, Mo, Si, Li, B, and Al is contained as a sub component and the substitution amount a of Zr as the main component is 0.30≤a≤1.00 has higher specific resistance and higher voltage resistance than Specimen No. 13 in which the substitution amount a of Zr as the main component is 0.30≤a≤1.00. Also in Specimen No. 63 to Specimen No. 65 produced using a Ni internal electrode by reductive atmosphere firing, it was possible to confirm that the specific resistance and the DC voltage resistance at 200° C. exhibit high values.

COMPARATIVE EXAMPLE

In Specimen No. 66 and Specimen No. 67 presented in Table 3, multilayer ceramic capacitors were produced using a tungsten bronze type composite oxide containing an alkali metal element as a main component. The specific manufacturing method will be described below. Incidentally, a specimen marked with ※ in Table 3 is a comparative example.

In Specimen No. 66 and Specimen No. 67, tungsten bronze type composite oxide K(Sr_(0.3)Ba_(0.3)Ca_(0.4))₂Nb₅O₁₅ powder containing an alkali metal element synthesized in advance was prepared as a main component, and MnCO₃ powder that is a raw material of a sub component to be added to the main component was prepared. Then, K(Sr_(0.3)Ba_(0.3)Ca_(0.4))₂Nb₅O₁₅ powder as the main component and MnCO₃ powder as the raw material of the sub component were weighed and mixed to have a predetermined ratio of the sub component to 100 mol of the main component, thereby preparing mixed powder.

The mixed powder of the main component and the sub component is used as a dielectric composition raw material.

A paste for a dielectric layer was produced in the similar manner to the example, except that the dielectric composition raw material was used, and a green sheet was formed on a PET film to have a thickness after drying of 7 μm. Then, an internal electrode layer was printed with a predetermined pattern on the green sheet using a paste for an internal electrode containing Ni as a main component, and then the sheet was peeled off from the PET film to produce a green sheet having an internal electrode layer. Subsequently, a green chip was obtained using the green sheet similarly to the example.

Then, the obtained green chip was subjected to a binder removal treatment (temperature increase rate: 10° C./hr, retention temperature: 350° C., temperature retention time: 8 hours, atmosphere: in nitrogen) and subjected to firing (temperature increase rate: 200° C./hr, retention temperature: 1100° C., temperature retention time: 2 hours, cooling rate: 200° C./hr, oxygen partial pressure: 10⁻⁹ to 10⁻¹² Pa, atmosphere: H₂—N₂—H₂O mixed gas) to obtain a multilayer ceramic fired body.

Both end faces of the obtained multilayer ceramic fired body were applied with a Ag paste containing B₂O₃—SiO₂—BaO-based glass frit and subjected to a baking treatment (temperature: 800° C., atmosphere: N₂ gas) to obtain multilayer ceramic capacitors of Specimen No. 66 and Specimen No. 67 having the same shape as the multilayer ceramic capacitor illustrated in FIGURE. The sizes of the obtained multilayer ceramic capacitors were all 4.5 mm×3.2 mm×0.5 mm, the thickness of the dielectric layer was set to 6.0 μm, the thickness of the internal electrode layer was set to 1.5 μm, and the number of the dielectric layers interposed between the internal electrode layers was set to 5.

As for the obtained multilayer ceramic capacitors of Specimen No. 66 and Specimen No. 67, similarly to the example, the specific permittivity, the specific resistance, and the DC voltage resistance were measured and the results thereof were presented in Table 3.

TABLE 3 Accessory component 25° C. 180° C. 200° C. 180° C. 200° C. [mol %] (with respect to Specific Specific Specific Voltage Voltage 100 mol of main component) permittivity resistance resistance resistance resistance Main component composition Mn [—] {Qcm] {Qcm] [V/μm] [V/μm] ^(※)Specimen No. 66 K(Sr_(0.3)Ba_(0.3)Ca_(0.4))₂Nb₅O₁₅ 40.00 1900 6.31E+09 1.51E+09 132 134 ^(※)Specimen No. 67 K(Sr_(0.3)Ba_(0.3)Ca_(0.4))₂Nb₅O₁₅ 5.00 1900 3.98E+09 9.56E+08 132 133

As presented in Table 3, it is possible to confirm that Specimen No. 66 and Specimen No. 67 that are a tungsten bronze type composite oxide containing an alkali metal element as a main component have low values of the voltage resistance and the specific resistance since a lattice defect caused by the alkali metal element with high volatility easily occurs and the conduction electron is easily generated.

INDUSTRIAL APPLICABILITY

The dielectric composition of the present invention can be applied under the environment close to an engine room as an in-vehicle electronic component since the dielectric composition has high DC voltage resistance, high specific resistance, and a long high-temperature load life in a high-temperature region of 200° C., and can be also applied to use application as an electronic component mounted in the vicinity of a power device using a SiC- or GaN-based semiconductor.

EXPLANATIONS OF LETTERS OR NUMERALS

-   -   1 MULTILAYER CERAMIC CAPACITOR     -   2 DIELECTRIC LAYER     -   3 INTERNAL ELECTRODE LAYER     -   4 EXTERNAL ELECTRODE     -   10 CAPACITOR ELEMENT MAIN BODY 

1. A dielectric composition comprising, as a main component, a tungsten bronze type composite oxide represented by a chemical formula (Sr_(1.00−s−t)Ba_(s)Ca_(t))_(6.00−x)R_(x)(Ti_(1.00−a)Zr_(a))_(x+2.00)(Nb_(1.00−b)Ta_(b))_(8.00−x)O_(30.00), wherein the R is at least one element selected from Y, La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu, and s, t, x, a, and b satisfy 0.50≤s≤1.00, 0≤t≤0.50, 0.50≤s+t≤1.00, 0.50<x≤1.50, 0.30≤a≤1.00, and 0≤b≤1.00.
 2. The dielectric composition according to claim 1, wherein at least one selected from Mn, Mg, Co, V, W, Mo, Si, Li, B, and Al is contained as a sub component in 0.10 mol or more and 20.00 mol or less with respect to 100 mol of the main component.
 3. The dielectric composition according to claim 1, wherein a substitution amount a of Zr in the chemical formula is 0.50≤a≤1.00.
 4. A dielectric element comprising the dielectric composition according to claim
 1. 5. An electronic component comprising a dielectric layer comprising the dielectric composition according to claim
 1. 6. A multilayer electronic component comprising a multilayer portion wherein a dielectric layer comprising the dielectric composition according to claim 1 and an internal electrode layer are stacked alternately. 